Despite the ever-increasing trend toward the manufacture and distribution of highly sophisticated automated toys and the like, the field of robotics--particularly, robots intended to simulate the movement of humans, humanoids, animals, alien beings, and the like--has remained essentially devoid of any robotic mechanism capable of actually walking and/or turning in a manner similar to that of the particular entity or creature being simulated. There are, on the other hand, highly sophisticated robotic mechanisms capable of efficiently simulating the movement of fingers, hands and arms with a high degree of accuracy; but, while efforts have been directed towards simulated walking and/or turning, the problem of balance has apparently been so resistant to solution, that most robots available in the marketplace today employ wheels and/or continuously driven tracks to enable the robot to move over the ground by rolling or gliding.
Nevertheless, while most robots available in the marketplace today employ wheels and/or tracks to permit movement over the ground, the prior art is replete with long-standing efforts to provide a robot capable of walking. As evidence.. of this fact, attention is directed to U.S. Pat. No. 335,302 issued to Peloubet in 1886--viz., more than one hundred years ago--wherein a two-legged walking doll, or biped, is disclosed in which the doll's balance is maintained by providing left and right feet which are of sufficient width that the doll's center of gravity is disposed above the supporting foot at all times.
In U.S. Pat. No. 882,403 issued to Mikolasek in 1908, a walking toy biped is disclosed wherein the toy's left and right legs are alternately raised and lowered by a crank assembly; and, in order to maintain the toy's balance, a liquid-filled weight is coupled to the crank assembly for shifting the toy's center of gravity laterally to the left or to the right over the ground engaged supporting leg.
Such arrangements apparently represented the general state of the art until the 1930's when U.S. Pat. Nos. 1,897,670-Melville and 1,986,446-Powelson issued disclosing toys having pendulously supported weights for maintaining the robot's balance. In 1958, U.S. Pat. No. 2,827,735 issued to H. E. Grimm, Jr. disclosing a six-legged animal wherein two legs on one side of the toy were coupled to, and driven by, the same mechanism as was coupled to, and which drove, one leg on the opposite side of the toy so as to maintain the toy's balance. And, in 1961, U.S. Pat. No. 3,010,729 issued to Tomosy disclosing a four-legged walking toy wherein the legs were actuated using a cam-actuated rack and pinion assembly.
A robot amusement ride is disclosed in U.S. Pat. No. 3,093,372 issued in 1963 to Cirami wherein the robot's legs are crank operated and the robot is stabilized by physically connecting it to a continuous external supporting track. Other crank-actuated robotic mechanisms disclosed during the 1960's are found in U.S. Pat. Nos. 3,223,461 and 3,302,883, both of which issued to W. H. Stout and which disclose ambulatory irrigation systems.
More recently, U.S. Pat. Nos. 3,660,931-Gardel et al, 4,365,437-Jameson, and 4,834,200-Kajita have issued presumably disclosing state-of-the-art robotic technologies. In Gardel et al, issued in 1972, a walking doll is disclosed having legs mounted at an angle to the axis of the doll's torso so that as the legs move relative to the body, the body tilts to shift the center of gravity of the doll over the leg planted on the floor. In the Jameson Patent issued in 1982, the legs of the toy are crank-operated and a gyroscope is provided to prevent rotation and maintain stability. The Kajita Patent, which issued in May of 1989, discloses a walking robot wherein the lengths of the robot's legs and the angles between each foot and leg are continuously adjusted so as to maintain the robot's center of gravity within the support area defined by the robot's footprint.
However, notwithstanding the state-of-the-art as exemplified by the foregoing patents, no known prior art robot exists, either in the patented or published art, or in the form of a commercially available robot, wherein the robot is capable of walking in a manner similar to that of a human being--i.e., by lifting a first foot/leg assembly off the ground, striding forward with the raised first foot/leg assembly while the weight of the robot is supported by the ground-engaged second foot/leg assembly and replanting the raised first foot/leg assembly on the ground in advance of the second foot/leg assembly, and replicating the foregoing steps alternately with the second and first foot/leg assemblies so that the robot walks either in a straight line or in any desired non-linear path from Point "A" to Point "B". Rather, despite such prior art patent teachings, conventional robotic wisdom generally requires the use of wheels or moving tracks to enable a robot to roll or glide from Point "A" to Point "B"--requirements that are necessitated by the need to keep the robot from falling over due to shifting of its center of gravity.
The foregoing deficiencies in the prior art have clearly been recognized by persons skilled in the art. Thus, as stated in an article entitled "Scale Effects, A Livelihood Modeled After . . . Models-" written by January Anderson and appearing in a publication entitled "Central Coast", published by R J NELSON ENTERPRISES, INC. of Santa Maria, Calif., November, 1989 Edition, at pages 24-27:
"Another Scale Effects project is the perfection of what is known in the movie industry as a `walker,` a multi-limbed mechanical creature, such as marching four-legged robots seen in space fantasy movies. PA1 "The problem is that movie `walkers` do not actually walk. A living two-legged or four-legged creature experiences considerable shifts in the weight of its body with each step, but uses its muscles to counter-balance it. As of yet, however, no one has been able to make a mechanical walker that will not tumble to the ground when its weight shifts. As a consequence, film makers must make the walkers appear to move across the screen by use of `stop motion` photography in which a still shot is made, the walker model is moved slightly by hand, another still shot is made, and so forth. It is a long and tedious process." (Central Coast, November, 1989, page 24 at page 26.)